For starters, how about that title? Is that a grabber? Doesn't it make you want to run out and spend a few hours looking at four guys in green latex turtle suits, with little color-coordinated red, blue, orange and yellow bandit masks, yelling "Yo!" and "Dude!" and snapping off karate kicks?

No? Well, anyway, they're back . . . in time. And back . . . in mindlessness. But they haven't gone back . . . far enough, because, somehow, we can still see them.

In this $20-million sequel to a sequel, which the distributors deliberately kept away from critics before its Friday opening, Donatello, Raphael, Michelangelo and Leonardo--who owe their genesis to comic team Kevin Eastman and Peter Laird, and their vast popularity to one of those marketing blitzes that seem to pulverize intellect--bumble their way into a staggeringly expensive, obtuse and irrelevant parody of a period samurai epic.

*

Using the device of a magical scepter, which simultaneously transports someone back in time, while whisking someone else, of equal weight, forward, writer-director Stuart Gillard hurtles the turtles and their pal April back to the 14th Century, while five bewildered samurai warriors loll around in the turtles' contemporary New York sewer hideaway, hypnotized by TV hockey games.

This is really Sequel Hell. Back in the past, villains snarl. Swords flash. Topknots quiver. Horses race through the forest. Samurai Lord Norinaga (Sab Shimono)--who looks so much like Wayne Newton that one of the turtles yells "Hey! It's Wayne Newton!"--grunts and glowers. A swaggering British freebooter (Stuart Wilson) named Capt. Dirk, sneers, struts and double-crosses everybody. Feisty feminist newswoman April (Paige Turco) insults every man in sight and gets hoisted up in a small cage, guarded by a 300-pound jailer, who swaggers around in his underwear.

And through it all, the four turtle dudes, trying to find the missing scepter, wander through the forest, scale fortress walls, crack wise, bop baddies and fall in love with rebel girls.

*

Whatever magic the first two movies may have had--and it wasn't always that apparent to anyone over the age of 10--has long since congealed, like stale pizza. Or mock turtle soup.

Previously, the turtles functioned, however dubiously, as fantasy figures and weirdo pop culture anachronisms. But Gillard's love of samurai epics--and he obviously does love them--has betrayed him. Shot by the fine Israeli cinematographer David Gurfinkel, this film captures the look of a standard samurai movie, even the burnished, lamplit storybook gleam of the better '50's pirate movies. The turtle costumes themselves, designed long ago at the Jim Henson factory, still have a lovable Kermit-esque charm.

But looks aren't everything. And, after 10 minutes or so of tortoise levity here, they seem as disposable as everything else. "Teenage Mutant Ninja Turtles 3: The Turtles Are Back . . . In Time" (MPAA rated PG) is a movie that's just as witty, entertaining and full of surprises as its title. Unfortunately, it's longer.